From 465e5e6a1698f3325f5d2262d2875779b06b50c7 Mon Sep 17 00:00:00 2001 From: Pankaj Raghav Date: Mon, 17 Apr 2023 14:36:15 +0200 Subject: fs/buffer: add folio_set_bh helper Patch series "convert create_page_buffers to folio_create_buffers". One of the first kernel panic we hit when we try to increase the block size > 4k is inside create_page_buffers()[1]. Even though buffer.c function do not support large folios (folios > PAGE_SIZE) at the moment, these changes are required when we want to remove that constraint. This patch (of 4): The folio version of set_bh_page(). This is required to convert create_page_buffers() to folio_create_buffers() later in the series. Link: https://lkml.kernel.org/r/20230417123618.22094-1-p.raghav@samsung.com Link: https://lkml.kernel.org/r/20230417123618.22094-2-p.raghav@samsung.com Signed-off-by: Pankaj Raghav Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Hannes Reinecke Cc: Alexander Viro Cc: Christian Brauner Cc: Luis Chamberlain Signed-off-by: Andrew Morton --- fs/buffer.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 9e1e2add541e..009d950fbf42 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1485,6 +1485,21 @@ void set_bh_page(struct buffer_head *bh, } EXPORT_SYMBOL(set_bh_page); +void folio_set_bh(struct buffer_head *bh, struct folio *folio, + unsigned long offset) +{ + bh->b_folio = folio; + BUG_ON(offset >= folio_size(folio)); + if (folio_test_highmem(folio)) + /* + * This catches illegal uses and preserves the offset: + */ + bh->b_data = (char *)(0 + offset); + else + bh->b_data = folio_address(folio) + offset; +} +EXPORT_SYMBOL(folio_set_bh); + /* * Called when truncating a buffer on a page completely. */ -- cgit v1.2.3 From c71124a8afa441af203d2001a92c91f114446687 Mon Sep 17 00:00:00 2001 From: Pankaj Raghav Date: Mon, 17 Apr 2023 14:36:16 +0200 Subject: buffer: add folio_alloc_buffers() helper Folio version of alloc_page_buffers() helper. This is required to convert create_page_buffers() to folio_create_buffers() later in the series. alloc_page_buffers() has been modified to call folio_alloc_buffers() which adds one call to compound_head() but folio_alloc_buffers() removes one call to compound_head() compared to the existing alloc_page_buffers() implementation. Link: https://lkml.kernel.org/r/20230417123618.22094-3-p.raghav@samsung.com Signed-off-by: Pankaj Raghav Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Hannes Reinecke Cc: Alexander Viro Cc: Christian Brauner Cc: Luis Chamberlain Signed-off-by: Andrew Morton --- fs/buffer.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 009d950fbf42..bbd4aa670262 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -843,7 +843,7 @@ int remove_inode_buffers(struct inode *inode) } /* - * Create the appropriate buffers when given a page for data area and + * Create the appropriate buffers when given a folio for data area and * the size of each buffer.. Use the bh->b_this_page linked list to * follow the buffers created. Return NULL if unable to create more * buffers. @@ -851,8 +851,8 @@ int remove_inode_buffers(struct inode *inode) * The retry flag is used to differentiate async IO (paging, swapping) * which may not fail from ordinary buffer allocations. */ -struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, - bool retry) +struct buffer_head *folio_alloc_buffers(struct folio *folio, unsigned long size, + bool retry) { struct buffer_head *bh, *head; gfp_t gfp = GFP_NOFS | __GFP_ACCOUNT; @@ -862,12 +862,12 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, if (retry) gfp |= __GFP_NOFAIL; - /* The page lock pins the memcg */ - memcg = page_memcg(page); + /* The folio lock pins the memcg */ + memcg = folio_memcg(folio); old_memcg = set_active_memcg(memcg); head = NULL; - offset = PAGE_SIZE; + offset = folio_size(folio); while ((offset -= size) >= 0) { bh = alloc_buffer_head(gfp); if (!bh) @@ -879,8 +879,8 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, bh->b_size = size; - /* Link the buffer to its page */ - set_bh_page(bh, page, offset); + /* Link the buffer to its folio */ + folio_set_bh(bh, folio, offset); } out: set_active_memcg(old_memcg); @@ -899,6 +899,13 @@ no_grow: goto out; } +EXPORT_SYMBOL_GPL(folio_alloc_buffers); + +struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, + bool retry) +{ + return folio_alloc_buffers(page_folio(page), size, retry); +} EXPORT_SYMBOL_GPL(alloc_page_buffers); static inline void -- cgit v1.2.3 From 8e2e17560bed73c2a73c94cbe378719f6cf850ee Mon Sep 17 00:00:00 2001 From: Pankaj Raghav Date: Mon, 17 Apr 2023 14:36:17 +0200 Subject: fs/buffer: add folio_create_empty_buffers helper Folio version of create_empty_buffers(). This is required to convert create_page_buffers() to folio_create_buffers() later in the series. It removes several calls to compound_head() as it works directly on folio compared to create_empty_buffers(). Hence, create_empty_buffers() has been modified to call folio_create_empty_buffers(). Link: https://lkml.kernel.org/r/20230417123618.22094-4-p.raghav@samsung.com Signed-off-by: Pankaj Raghav Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Hannes Reinecke Cc: Alexander Viro Cc: Christian Brauner Cc: Luis Chamberlain Signed-off-by: Andrew Morton --- fs/buffer.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index bbd4aa670262..e6266bf7eeea 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1594,18 +1594,17 @@ out: } EXPORT_SYMBOL(block_invalidate_folio); - /* * We attach and possibly dirty the buffers atomically wrt * block_dirty_folio() via private_lock. try_to_free_buffers - * is already excluded via the page lock. + * is already excluded via the folio lock. */ -void create_empty_buffers(struct page *page, - unsigned long blocksize, unsigned long b_state) +void folio_create_empty_buffers(struct folio *folio, unsigned long blocksize, + unsigned long b_state) { struct buffer_head *bh, *head, *tail; - head = alloc_page_buffers(page, blocksize, true); + head = folio_alloc_buffers(folio, blocksize, true); bh = head; do { bh->b_state |= b_state; @@ -1614,19 +1613,26 @@ void create_empty_buffers(struct page *page, } while (bh); tail->b_this_page = head; - spin_lock(&page->mapping->private_lock); - if (PageUptodate(page) || PageDirty(page)) { + spin_lock(&folio->mapping->private_lock); + if (folio_test_uptodate(folio) || folio_test_dirty(folio)) { bh = head; do { - if (PageDirty(page)) + if (folio_test_dirty(folio)) set_buffer_dirty(bh); - if (PageUptodate(page)) + if (folio_test_uptodate(folio)) set_buffer_uptodate(bh); bh = bh->b_this_page; } while (bh != head); } - attach_page_private(page, head); - spin_unlock(&page->mapping->private_lock); + folio_attach_private(folio, head); + spin_unlock(&folio->mapping->private_lock); +} +EXPORT_SYMBOL(folio_create_empty_buffers); + +void create_empty_buffers(struct page *page, + unsigned long blocksize, unsigned long b_state) +{ + folio_create_empty_buffers(page_folio(page), blocksize, b_state); } EXPORT_SYMBOL(create_empty_buffers); -- cgit v1.2.3 From c6c8c3e7b47d7d20952202e7568389a5e3b043dd Mon Sep 17 00:00:00 2001 From: Pankaj Raghav Date: Mon, 17 Apr 2023 14:36:18 +0200 Subject: fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer do not support large folios as there are many assumptions on the folio size to be the host page size. This conversion is one step towards removing that assumption. Also this conversion will reduce calls to compound_head() if folio_create_buffers() calls folio_create_empty_buffers(). Link: https://lkml.kernel.org/r/20230417123618.22094-5-p.raghav@samsung.com Signed-off-by: Pankaj Raghav Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Hannes Reinecke Cc: Alexander Viro Cc: Christian Brauner Cc: Luis Chamberlain Signed-off-by: Andrew Morton --- fs/buffer.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index e6266bf7eeea..b0b8c5fba691 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1723,14 +1723,17 @@ static inline int block_size_bits(unsigned int blocksize) return ilog2(blocksize); } -static struct buffer_head *create_page_buffers(struct page *page, struct inode *inode, unsigned int b_state) +static struct buffer_head *folio_create_buffers(struct folio *folio, + struct inode *inode, + unsigned int b_state) { - BUG_ON(!PageLocked(page)); + BUG_ON(!folio_test_locked(folio)); - if (!page_has_buffers(page)) - create_empty_buffers(page, 1 << READ_ONCE(inode->i_blkbits), - b_state); - return page_buffers(page); + if (!folio_buffers(folio)) + folio_create_empty_buffers(folio, + 1 << READ_ONCE(inode->i_blkbits), + b_state); + return folio_buffers(folio); } /* @@ -1774,8 +1777,8 @@ int __block_write_full_page(struct inode *inode, struct page *page, int nr_underway = 0; blk_opf_t write_flags = wbc_to_write_flags(wbc); - head = create_page_buffers(page, inode, - (1 << BH_Dirty)|(1 << BH_Uptodate)); + head = folio_create_buffers(page_folio(page), inode, + (1 << BH_Dirty) | (1 << BH_Uptodate)); /* * Be very careful. We have no exclusion from block_dirty_folio @@ -2038,7 +2041,7 @@ int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len, BUG_ON(to > PAGE_SIZE); BUG_ON(from > to); - head = create_page_buffers(&folio->page, inode, 0); + head = folio_create_buffers(folio, inode, 0); blocksize = head->b_size; bbits = block_size_bits(blocksize); @@ -2324,7 +2327,7 @@ int block_read_full_folio(struct folio *folio, get_block_t *get_block) VM_BUG_ON_FOLIO(folio_test_large(folio), folio); - head = create_page_buffers(&folio->page, inode, 0); + head = folio_create_buffers(folio, inode, 0); blocksize = head->b_size; bbits = block_size_bits(blocksize); -- cgit v1.2.3